42 research outputs found

    Repairing of exit-hole in dissimilar Al-Mg friction stir welding : process and microstructural pattern

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    The exit-hole is one major discontinuities in the friction based processes, where all the volume of the tool's probe is missing with a depth that corresponds to the full thickness of the processed component. This letter presents a new technique to repair the exit-hole of an Al-Mg friction stir welding, without any third body material with inexpensive probeless tooling, inducing forging, stirring, and thermomechanical consolidation of the local spot joint. Intercalated banned type structures with interpenetrating features were achieved. Composite type mixed structure was obtained at repaired zone with a local tensile strength of 159 MPa

    Accuracy of spontaneous breathing trial using ET-CPAP in predicting successful extubation of neonates

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    Objective: Extubation failure is common in mechanically ventilated neonates. Finding objective criteria for predicting successful extubation may help to reduce the incidence of failure and the length of mechanical ventilation (MV). We conducted this study to determine the accuracy of the spontaneous breathing trial (SBT) and lung function measurements in predicting successful extubation in neonates.Methodology: This cross-sectional validation study was conducted at a tertiary care neonatal intensive care unit (NICU) over 12 months from December 2019 to December 2020. Neonates intubated for \u3e24 hours and considered ready for extubation were enrolled in the study. Neonates who met defined eligibility criteria underwent a three minutes SBT using endotracheal continuous positive airway pressure (ET-CPAP) before extubation. The primary clinical team was blinded to the results, and all neonates were extubated after SBT. Extubation was considered successful if patients remained extubated for 48 hours.Results: Among the 107 infants, 77.5% (n=83) of infants passed the SBT. Of these, 78 were successfully extubated, giving the positive predictive value of 93.97%. The overall extubation success rate was 90% (n=96). The sensitivity and specificity of SBT were 81.2% and 54.5%, respectively. VE (ET-CPAP) and VE-ventilator at a cutoff of ≥238 ml and ≥143.7 ml have an area under the curve (AUC) of 0.77 and 0.75 respectively to predict successful extubation (p-value 0.003, 0.008 respectively).Conclusion: SBT predicts extubation success with pronounced accuracy. Therefore, we propose SBT as a valuable and crucial step that guides clinicians\u27 decision-making regarding extubation preparedness or impending failure in neonates

    Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

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    Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

    Postoperative outcomes in oesophagectomy with trainee involvement

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    BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery

    Prefabrication in Building Construction: A Perspective of Pakistan Construction Industry

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    Construction industry is facing many problems in terms of construction waste, quality, environment, durability, safety and higher construction cost. Adoption of prefabrication is a possible solution to such problems. Accordingly, there is a need to study the prospects that would stimulate the appropriate discussion of the suitability of prefabrication and other construction methods for concrete buildings. Therefore, this study investigates the significance of advantages in adopting prefabrication along with hindrances through questionnaire survey. The data has been analyzed using RIW (Relative Importance Weight) method as a MCDM approach. The results depict that main advantages of prefabrication are ?Shorter construction time? and ?Less construction site waste?. The top hindrances in adopting prefabrication as identified in this study are: ?Higher initial construction cost? and ?Inflexible for design changes?. Based on the survey results and apparent progress in the adoption of prefabrication around the world, it is concluded that the use of prefabrication is likely to increase in developing countries like Pakista

    Adoption of Value Engineering: An Attribute Study for Construction Industry of Pakistan

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    For economic reasons, engineers are compelled to explore low cost methods in construction industry to reduce the overall cost of a project. Research studies have been conducted in this regard throughout the world and value engineering is one of such approaches. Its effective use and applications reduces the project cost without compromising the project quality. Project cost, and efficient design alternatives can be identified using this technique, which will ultimately reduce the overall project cost. Client satisfaction, project reliability and quality can also be improved by the application of value engineering. It is also used for improving managerial performance, project schedule and reduced risks in a project. It is a powerful tool used to identify problems and recommend solutions. This paper highlights the importance of value engineering in general and with specific perspective of Construction Industry in Pakistan. Questionnaire based survey has been conducted by construction managers (i.e. project engineers, construction engineers, project managers, architects, etc.) through online web based system, as a result, random data sampling is achieved. The attributes are mapped to obtain goals for the project. The data has been analyzed through reliability and linear regression using SPSS while Z-Score and Average Index are conducted using MS Excel. The results showed that there is ample need to apply such techniques in initial phases of any project to get project benefits

    Clustering Approaches for Efficient Radio Resource Management in Heterogeneous Networks

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    5G telecommunication industry promises to manage and accomplish the massive data traffic and growing network requirement complexities in heterogeneous networks (HetNets). HetNets are K-tier networks and are expected to be seamlessly connected networks with robust services for users anywhere at any time. In near future, the significance of 5G/B5G cellular networks; in both indoor and outdoor environments will be greater than before and it would add up to an exhaustive level. However, as a result of the increased density of networks, a rise in interference within these ultra-dense networks (UDN) will have an alarming impact on throughput, interference and latency.  To ensure high throughput with reduced interference in UDNs a clustered architecture is required. A HetNet with clustered approach enables the network to mitigate interference effectively and achieve efficient radio resource management (RRM). In this paper, we analyzed different clustering classifications and existing clustering techniques that are used for proficient radio resource management. The centralized clustering techniques and decentralized clustering techniques are analyzed and as a result, it is assumed that improved performance can be achieved by emphasizing on hybrid clustering approaches. In addition to this, performed a thoughtful review of existing hybrid clustering techniques to achieve improved throughput and mitigate interference in dense heterogeneous networks.  Our analysis shows that improved radio resource management and increased throughput in HetNets is achieved by applying hybrid clustering techniques with reduced inter and intra tier interference.

    Attribute Hierarchy of Conflicts in Construction Projects: A Case Study of Sindh

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    Conflicts seem to arise throughout the life cycle of the construction project and in result, these may lead to several other issues such as project cost overrun, time overrun, productivity loss, loss of profit and above all damage of business relationships in general and specifically in construction industry. Hence, this paper focuses on various direct and indirect causes leading to conflicts in construction industry of Sindh, Pakistan. Detailed literature review and interviews have been carried out to identify several direct and indirect causes of conflicts and finally, a set of questionnaire has been designed and distributed to get expert opinion on the significance of these causes in this sector. The data has been analyzed by RIW (Relative Importance Weight) method. The outcome of this study shows that payment delay is the major direct cause of conflicts in the construction projects followed by contractual claims, public interruption, poor communication and site conditions. Thus, it is suggested that proper attention should be given to the above mentioned concerns so as to have a uniform flow of construction project life cycle without any interruption

    Public Sector Education Institution's Analysis: A Way Forward to Curtail Rural-Regional Education Accessibility Problems

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    The availability of accessible educational facilities is essential for the better rural education. However, because of the huge population, lack of resources and absence of proper policy plans; the distance between educational facilities and rural communities is mounting as time progresses. These sorts of problematic circumstances put damaging effects on education standards and become responsible for the declining literacy rate. Hence, the goal of this research is to investigate the lack of educational institutions with respect to indigenous standards. Therefore, in this study, the dearth of education institutions was determined for the one of the most deprived sub-regions of Pakistan, i.e. Badin. The data were collected through observations, questionnaire survey, and from secondary sources, like census report and other pertinent public sector documents. The outcome of this study can be taken as an input to develop policy plans, targeting the education accessibility issues of backward communities. This research could show a guiding-path to local planning agencies, as these can come-up with the policy plans to trounce the education accessibility issues from the bucolic sub-regions of developing countrie
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